.\"                                      Hey, EMACS: -*- nroff -*-
.TH VJPEG 1 "Feb 26, 2018"
.SH NAME
vjpeg \- visual tool to experience the compression parameter available in sjpeg.
.SH SYNOPSIS
.B vjpeg
.RI [ options ] " input_file
.br
.SH DESCRIPTION
This manual page documents the
.B vjpeg
command.
.PP
\fBvjpeg\fP compresses a PNG, JPEG or PPM image or recompresses a JPEG image, using
the baseline JPEG format and a visual interface based on OpenGL.
.SH OPTIONS
The basic options are:
.TP
.B \-h, \-help
A summary of all the possible options.
.TP
.B \-version
Print the SimpleJPEG's library version number (as major.minor.revision) and exit.
.TP
.B \-q " int
Specify the compression factor between 0 and 100. The default
is 75.
A small factor produces a smaller file with lower quality.
.TP
.B \-info
Overlay some file information on the display.

.SH KEYS
The available key shortcuts are:
.IP
   'i' ............... overlay file information
.IP
   ' ' ............... show the original uncompressed picture
.IP
   up/down ........... change the compression factor by +/- 1 units
.IP
   left/right ........ change the compression factor by +/- 10 units
.IP
   return ............ show alternate picture (if specified)
.IP
   0/1/2/3 ........... change the yuv_mode to auto/yuv420/sharp-yuv420/yuv444
.IP
   'o' ............... toggle Huffman optimization
.IP
   'a' ............... toggle adaptive quantization
.IP
   'b' ............... toggle adaptive bias
.IP
   'l' ............... toggle quantization limitation
.IP
   't' ............... toggle trellis-based quantization
.IP
   'e' ............... show error map
.IP
   'r' ............... show riskiness map
.IP
   '+'/'-' ........... go to next/previous file
.IP
   'h' ............... show this help message
.IP
   'q' / 'Q' / ESC ... quit

Just press 'h' for help.

.SH BUGS
Please report any bugs to the SJPEG discussion list:
https://groups.google.com/forum/#!forum/sjpeg
The issue tracker is located at:
https://github.com/webmproject/sjpeg/issues
.br
Patches welcome! See this page to get started:
http://www.webmproject.org/code/contribute/submitting-patches/

.SH EXAMPLES
vjpeg \-q 50 picture.png

.SH AUTHORS
\fBvjpeg\fP was written by Pascal Massimino.
.br
The latest source tree is available at http://www.webmproject.org/code
.PP
This manual page was written by Pascal Massimino <pascal.massimino@gmail.com>,
for the Debian project (and may be used by others).

.SH SEE ALSO
.BR sjpeg (1)
.br
